1. Field of the Invention
The present invention relates to a substrate for mounting an IC chip and a device for optical communication.
2. Discussion of the Background
In recent years, optical fibers have been drawing attention as the center of the field of communications. In particular, communication technology using optical fibers has become necessary in the field of IT (information technology), for the development of high-speed Internet networks.
The optical fiber has characteristics of (1) low loss, (2) high band, (3) small diameter and light weight, (4) non-induction, (5) resource saving, and the like. A communication system which employs the optical fibers having these characteristics can considerably decrease the number of relays as compared with a communication system which employs conventional metallic cables, can be easily constructed and maintained, and can improve its economical efficiency and reliability.
Further, since the optical fiber can transmit not only light having a single wavelength but also light having a number of different wavelengths simultaneously, a large capacity of a transmission line which can deal with diversified purposes and tends to deal with picture service and the like can be achieved.
Therefore, for the network communication such as the Internet, the employment of optical transmission using optical fibers not only for the communication of a basic network but also for the communication between the basic network and terminal device (a personal computer, a mobile, a game machine and the like) and for the communication between the terminal devices is proposed.
Conventionally, as an optical transmitter receiver system, an optical transmitter receiver system is disclosed in which for example, a pair of planar light emitting and receiving elements are mounted with the face facing downwards using a flip chip bonding method on the surface of a multilayer substrate (substrate for a motherboard), through holes having a core portion and a clad portion right under the center of the planar light emitting and receiving elements are formed therein, and furthermore, the optical waveguide which linearly extends even from right under one through hole to right under the other through hole is formed on the bottom surface of the planar light emitting and receiving element (see for example JP-A 2000-81524).
The contents of JP-A 2000-81524 are incorporated herein by reference in their entirety.